Internet Download Protocol's Analysis And Implementation

Network protocol is in accordance with the rules of engagement to achieve some kind of network application activities.To meet the diverse needs of people, the Internet experts design a lot of agreement.Based on client-server models, HTTP protocol and FTP protocol make people enjoy the convenience of network resources in accordance with such rules.BitTorrent based P2P file distribution protocol allows individuals sharing.Meeting the demand in rich media age, RTMP protocol's real time and compression feature make it dominate.When people want to access application data based on these protocols,they need to analyze these protocols and develop a tool called downloader.This thesis summarizes the two basic models of network structure and multi-thread under Linux environment,researchs and analyzes four representative agreement:HTTP and FTP protocol of traditional network, file Distribution BitTorrent protocol and the improved protocol, Rich Internet Applications RTMP protocol.Based on the analysis of the above technology, the download system Mtdown is designed and realized with Linux platform and has a good performance compared with other download software. A kind of hard disk buffer management was improved to reduce the frequency of reading disk. At last, the improved hard disk buffer management was adopted in RTMP downloader.